Toroidally wound electrodynamic machines consist of stator and rotor, the stator being formed from a toroidal electromagnetic core with a coil or coils wound upon that core, the coil axis being substantially tangential to the core. Such stators are by their very nature relatively difficult to construct, in that complex equipment is required to form the windings about the core.
To overcome this difficulty some manufacturers have wound the coils onto multiple separate bobbins using simple winding equipment, and the wound bobbins are later introduced onto a split magnetic core. The two ends of the wires of each coil must then be electrically connected in a correct relationship with other coils forming a ring of electromagnets. This has been accomplished previously by connecting each wire to a circular printed circuit board with the conductive paths on the printed circuit board being designed to provide the required connections of the coils in the group. Alternatively the wires are individually connected by methods such as insulation displacement connectors. However this process can be complex and expensive.